407 



gas is held in solution by the water by an affinity which can be over- 

 come, and that the foreign matter which, with the carbon, formed the 

 sugar, or other vegetable substance, is then at liberty to form new 

 combinations. He finds that the products resulting from the decom- 

 position exceed the weight of the sugar, or other vegetable matter, 

 by about 10 per cent, of the former, and from 11 to 12 per cent, of 

 the latter, as calculated according to the prevailing theory that sugar, 

 or vegetable matter, is the only substance decomposed during the 

 process of vinous fermentation. 



From his analysis of sugar he obtains certain proportions of water 

 and of carbonic acid which are different from those given by preceding 

 chemists, the carbonic acid being 45 to 45*5 per cent. His analysis 

 of alcohol gives him 59'7 to 60 per cent, of olefiant gas, the remain- 

 der being water. 



His experiments on the acetous and putrefactive fermentations are 

 numerous and elaborate, and the results, which are nearly the same 

 as those of former analyses, are given in a tabular form. He finds 

 that in the acetous fermentation 57 parts by weight of olefiant gas, 

 5 of sugar, or other vegetable matter, and 64 of oxygen from the at- 

 mosphere, combine to form 100 parts of acetic acid, and about 24 of 

 water; leaving an insoluble substance at liberty to form other com- 

 binations : and thus includes in his account of this process the decom- 

 position of vegetable matter, which is overlooked in the generally re- 

 ceived theory. 



During the putrefactive fermentation of vinous fermented liquors, 

 when exposed to the atmosphere, the author considers that one equi- 

 valent of carbon from the olefiant gas (= 6*12) unites with two of 

 oxygen from the atmosphere (= 16") to form 22*12 parts of carbonic 

 acid : while one equivalent of hydrogen from the olefiant gas (= 1*) 

 combines with one of atmospheric oxygen (=8') to form 9 parts of 

 water ; a portion of sugar, or other vegetable matter, being also de- 

 composed ; and an insoluble substance remaining, which, on exposure 

 to the air, undergoes further decomposition, and forms products highly 

 deleterious. The author is not aware that this latter decomposition 

 has been hitherto noticed. 



During the putrefactive fermentation of acetic acid exposed to the 

 atmosphere, he regards one equivalent of carbon from acetic acid 

 (= 6' 12) as combining with two of atmospheric oxygen (= 16') to 

 form 22- i 2 parts of carbonic acid : the oxygen and hydrogen, with 

 which the carbon had formed the acetic acid, remain in the state of 

 water, as they are found by analysis in this substance : a portion of 

 vegetable matter is also decomposed ; and an insoluble substance left 

 behind. Other substances are also formed during some of the changes 

 resulting from exposure to the air. 



During the direct, putrefactive fermentation of solutions of sugar, 

 or other vegetable matters, he finds, that one equivalent of its car- 

 bon (= 6*12) unites with two of atmospheric oxygen (= 16 ) to 

 form 22- 1 2 parts of carbonic acid ; leaving the water and an insoluble 

 substance to undergo changes as before mentioned. The olefiant gas, 

 formed during the vinous fermentation, whether the liquor be in the 



